Hi Yu-ning, > This is line 49 in Makefile. Line 51 says, > > revision=`sed -e 's/^0$$//' -e 's/^[1-9].*$$/.&/' $(top_srcdir)/REVISION` > > I wonder the meaning of $$.
In makefiles, one writes `$$' to have a single `$' be passed to the shell. Otherwise, `echo $HOME' would tell make to execute `echo fooOME' if the *make* variable `H' was equal to `foo'. Cheers, Ralph.
